You can buy harissa paste from the supermarket - the strength will differ depending on the brand you buy - sorry, I can't help you here, you'll have to start with a small amount then add more to taste.
The pulped tomato - you can use a can of plum tomatoes which you can mash - add a tablespoon of tomato puree to intensify the tomato flavour if you like.
It would be great with potatoes and cooked vegetables or just buy a crusty french loaf to use to mop up the sauce.
Any white fish will do here - I've suggested basa, but you could use cod, haddock, pollack, whiting - anything non oily.
Skin and bone the fillets before you put it in the sauce.
1lb (450g) basa fish fillets - cut into large chunks
1 pint (600ml) pulped tomato
harissa to taste - start with 1/2 tspn
large handful of chopped coriander leaves or parsley
Put the tomato sauce, harissa and herbs into a pan - bring to the boil.
At this point, you need to taste the sauce - add some more paste if you want to and then bring it back up to simmering point so that the flavours combine.
Remove from the heat and add the fish. Simmer for about 5 minutes until the fish is cooked through.
Taste and adjust the seasoning, adding a bit more harissa paste if you want to.
Slice some bread and put on top to mop up some sauce.
Serve this with some boiled potatoes and fresh veg - a good hearty seafood stew.
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